CDC Nods off on Covid Shot Boosters for Vulnerable

16.08.2021 - As the delta variant of the coronavirus tears through the US, pushing both new and breakthrough infections higher, the US Centers for Disease Control (CDC) has now come out in favor of recommending that vulnerable individuals be given booster shots.

After straddling the line for several weeks, on Aug. 13 director Rochelle Walensky said she had signed off on the recommendation of the health organization’s Advisory Committee on Immunization Practices’ (ACIP) that an additional dose of an mRNA vaccine for people with moderately to severely compromised immune systems could be useful after an initial two-dose vaccine series.

A day earlier, the US Food and Drug Administration (FDA) amended the Emergency Use Authorizations for the Moderna and the Pfizer-BioNTech Covid-19 vaccines to allow some people with compromised immune systems to get a third dose.

Emerging data suggest some people with moderately to severely compromised immune systems do not always build the same level of immunity as those who are not immunocompromised. In addition, in small studies, fully vaccinated immunocompromised people have accounted for a large proportion of hospitalized breakthrough cases (40-44%), the CDC said.

Those concerned, seen to make up not quite 3% of the US adult population, include recipients of organ or stem cell transplants, people with advanced or untreated HIV infection, active recipients of cancer treatment, people who are taking some medications that weaken the immune system and others. 

A study looking at more than 18,000 fully vaccinated organ transplant recipients in the US is said to have found that they were 82 times more likely to get a breakthrough infection and 485 times more likely to have that infection lead to hospitalization or death, compared with the general population.

Last week’s decision does not apply to people who are not immunocompromised, the CDC stressed, noting that it does not recommend additional doses or booster shots for any other population at present. "If the data show in fact that the degree of protection has gone down below a critical level, that's when you're going to be hearing about the implementation of boosters in the general population,” President Joe Biden’s chief medical advisor, Anthony Fauci added.

The additional dose of an mRNA Covid-19 vaccine should be the same vaccine as the initial series and administered at least four weeks after completing a primary mRNA Covid-19 vaccine, the health organization said, although some are calling for the booster to be a different vaccine.

Commenting on a recent study that suggested US biotech Moderna’s vaccine was more effective against the delta variant than the Pfizer/BioNTech shot, Fauci said this does not indicate that people should seek a Moderna dose as a booster. He warned that study conducted by the Mayo Clinic and Cambridge, Massachusetts-based biotech Nfrence, which analyzed samples of delta variant prevalence in the US state of Minnesota from January to July 2021, had not yet been peer reviewed.

Author: Dede Williams, Freelance Journalist